Trung, Ha Duyen. “Estimation of Crowd Density Using Image Processing Techniques With Background Pixel Model and Visual Geometry Group”. Buletin Ilmiah Sarjana Teknik Elektro 6, no. 2 (June 20, 2024): 142–154. Accessed November 21, 2024. http://journal2.uad.ac.id/index.php/biste/article/view/10785.